Anterior vaginal wall prolapse: The challenge of cystocele repair
What’s the best strategy? Repairs often fail and the literature is inconclusive. Three experts analyze what we can learn from the limited studies to date, and offer tips on technique.
- At this time, the traditional anterior colporrhaphy with attention to apical suspension remains the gold standard.
- If only some defects of the anterior wall are addressed at the time of reconstructive surgery, failure may be more likely.
- Women with grade 3 or 4 cystoceles often have evidence of bladder outlet obstruction on urodynamic testing.
- In 52% of cases, cystoceles coexist with detrusor instability and evidence of impaired detrusor contractility.
- A thorough preoperative evaluation includes assessing the apex, having the patient strain to maximize the defect, looking for paravaginal detachments, and making every effort to “unmask” occult stress urinary incontinence.
Ask a pelvic reconstructive surgeon to name the most difficult challenge, and the answer is likely to be anterior vaginal wall prolapse. The reason: The anterior wall usually is the leading edge of prolapse and the most common site of relaxation or failure following reconstructive surgery. This appears to hold true regardless of surgical route or technique.
Short-term success rates of anterior wall repairs appear promising, but long-term outcomes are not as encouraging. Success usually is claimed as long as the anterior wall is kept above the hymen, since the patient rarely reports symptoms in these cases.
Another challenge involves the use of allografts or xenografts, which have not undergone sufficient study to determine their long-term benefit or risks in comparison with traditional repairs.
This article reviews anatomy of the anterior vaginal wall and its supports, as well as surgical technique and outcomes.
Why the anterior wall is more susceptible to prolapse
One theory is that, in comparison with the posterior compartment, the anterior wall is not as well supported by the levator plate, which counters the effects of gravity and abdominal pressure. Normally, the anterior wall rests horizontally on the posterior wall, which in turn rests on the levator plate. When the levator muscles weaken, the anterior wall is the first to fall as increasing force is placed on the connective tissue supports.
Other possibilities: The anterior compartment’s attachments to the pelvic sidewall or apex may be weaker, the anterior wall may be more elastic or less dense than the posterior wall, and the anterior wall may be more susceptible to damage during childbirth or to the effects of age and loss of estrogen.
If only some defects are addressed at surgery, failure may be more likely. Some experts believe pelvic surgeons have focused too much attention on the urethrovesical junction in patients with concomitant urinary incontinence and not enough attention on suspending the anterior wall at the apex.
For most women, it is probably a combination of many of these factors that renders the anterior compartment so vulnerable.
Anatomy of the pelvic floor
The anterior vaginal wall resembles a trapezoidal plane due to ventral and more medial attachments near the pubic symphysis, and dorsal and more lateral attachments near the ischial spine (FIGURE 1).1 This helps explain the many appearances of the cystocele. The type of cystocele is defined by the location of the break in the fascial attachments.
Paravaginal defects. The trapezoidal anterior wall is suspended on both sides from the parietal fascia overlying the levator ani muscles at the arcus tendineus fascia pelvis (ATFP). Prolapse can occur when there is loss of attachment to the pelvic sidewall at any point between the pubis and ischial spine.
First described by White2 and characterized later by Richardson et al,3 this loss of lateral attachment is called a paravaginal defect or displacement cystocele (FIGURE 2). The goal of paravaginal repair is to reattach the lateral vaginal walls to the ATFP, either abdominally, laparoscopically, or vaginally.
Central defects, the rarest type of anterior wall prolapse, involve a loss of support near the pubis and tend to be smaller. The most common manifestation is urethral hypermobility.
Transverse defects occur when the top of the pubocervical fascia detaches from the cervix or vaginal apex, both of which are suspended from the uterosacral-cardinal ligament complex. A transverse cystocele is evidenced by loss of the anterior fornix. The anterior wall appears to be attenuated in the midline, and the vaginal mucosa is pale, thin, and smooth (FIGURE 3).
Goals of traditional repair. The traditional anterior colporrhaphy aims to excise or reinforce the attenuated transverse defect with plication of the “endopelvic fascia” in the midline of the anterior vaginal wall. The endopelvic fascia is not true fascia but the muscularis of the vaginal wall. It is comprised of smooth muscle and elastin along with the collagenous adventitia layer.4
The importance of restoring apical wall support becomes apparent when one considers the trapezoidal anatomy. The most common sites of defects or detachments of the anterior wall are near the ischial spines laterally. In an operative case series of paravaginal defects, DeLancey1 found the site of defect to be near the ischial spine in 96% of cases. The reattachment of the apex near the level of the spine becomes the highest point of support for the anterior vaginal wall.
This cephalad apical attachment can be accomplished in a variety of ways, by suspending the vaginal apex from the uterosacral ligaments, from the sacrospinous ligament, or via abdominal sacrocolpopexy.
FIGURE 1 Anatomy of the anterior wall
The anterior vaginal wall resembles a trapezoidal plane, with ventral and more medial attachments near the pubic symphysis, and dorsal and more lateral attachments to the ischial spine. Detachment from the pelvic sidewall and ischial spine results in anterior wall prolapse (right).
FIGURE 2 Paravaginal defect
FIGURE 3 Transverse defect
A transverse defect with loss of the anterior fornix. The loss of cephalad apical attachment at the level of the ischial spine leads to anterior wall prolapse. Suspending the upper vagina from shortened cardinal/uterosacral ligaments, the sacrospinous ligament, or via abdominal sacrocolpopexy is as important as plication.
Symptoms of anterior wall prolapse
As with other forms of pelvic organ prolapse, many patients complain of a bulge or feeling of pelvic pressure when the anterior vaginal wall has come through the introitus. However, some symptoms of anterior wall prolapse are unique.
Incontinence is not universal. A common misperception is that most patients with cystocele also experience stress urinary incontinence (SUI), which can develop when there is loss of urethral support and descent of the lower vaginal wall along with urethral hypermobility. However, there is no defining degree of hypermobility that links anterior wall prolapse with SUI. That is because the continence mechanism relies not only on urethral position and lateral attachments, but also on the neuromuscular function of the pelvis and lower urinary tract.
In fact, descent of the midvagina under the bladder base may actually reduce the chance of SUI. The reason: As a woman strains, the increased abdominal pressure pushes the cystocele farther and farther out. As the cystocele enlarges, it creates a functional outlet obstruction by kinking the urethra shut. When this is the case, patients may complain of prolonged voiding, an intermittent urine stream, and/or urinary retention. The woman may have to elevate the vaginal wall to empty her bladder. Patients with chronic urinary retention are at risk of developing recurrent urinary tract infections.
Bladder outlet obstruction and detrusor dysfunction. Women with grade 3 or 4 cystoceles often have evidence of bladder outlet obstruction on urodynamic testing, according to a study that found such evidence in 57% of subjects.5 After reduction of the prolapse with a pessary, obstructed flow reverted to normal in 94% of these women.
A large proportion (52%) of women with cystoceles also have detrusor instability, as well as evidence of impaired detrusor contractility. Many complain of urinary frequency and urgency and difficulty emptying the bladder.5
Again, this phenomenon is complex, related not only to anatomy but to altered neuromuscular function of the lower urinary tract. Incomplete emptying, frequency, and urgency may arise from stretching of the bladder base as it prolapses through the vaginal introitus, resulting in urinary retention. These symptoms often are less pronounced at night when the patient is supine.
We reviewed 35 cases of anterior wall prolapse greater than 1 cm outside the hymen, with elevated postvoid residuals exceeding 100 cc on 2 separate occasions.6 Thirty-one (89%) had normal postvoid residuals following reconstructive surgery and correction of their anterior wall prolapse.
A careful physical exam is a prerequisite for all surgical repairs of pelvic organ prolapse. During this exam, identify the sites of defects and detachments.
Maximize the defect. Have the patient perform the Valsalva maneuver, cough, and/or strain while sitting upright or standing. As she is performing these maneuvers, ask her if this feels like her maximum prolapse. A split speculum often aids in visualizing the anterior and posterior compartments without pressure from the opposite vaginal wall.
Assess the apex. Place a large swab in the vagina, hold it gently against the apex, and ask the patient to strain. If the swab is pushed out, the apex needs suspension.
This technique can help identify apical relaxation that may be masked by a large anterior or posterior wall defect. A standardized staging system, such as the Pelvic Organ Prolapse Quantitative Examination (POP-Q) or Baden-Walker, aids in communicating and documenting the prolapse. In addition, it allows the surgeon to track anatomical outcomes after surgery.
Look for paravaginal defects by supporting the lateral anterior walls with a ring forceps at the level of the ATFP. Barber et al7 found this maneuver to be highly sensitive (90–94%): If no paravaginal defect was suspected clinically, none was found intraoperatively. However, the positive predictive value was poor (57%), in that defects suspected preoperatively were confirmed during surgery in less than two thirds of patients.
These findings point to the importance of careful intraoperative assessment, both before and during the repair procedure.
Limited utility of imaging studies. The use of radiologic studies such as defecography or dynamic magnetic resonance imaging of the pelvis may aid in the evaluation of defecatory disorders or suspected sigmoidocele or rectal prolapse, but have not been studied sufficiently to determine the impact on surgical outcome.
As mentioned above, women with anterior wall prolapse do not always complain of stress incontinence. However, correction of the cystocele can relieve their obstructive voiding and unmask “occult” SUI. Various techniques have been described to elevate the anterior wall with pessaries, swabs, etc, during urodynamic testing to predict which women should have an incontinence procedure performed at the time of reconstructive surgery.
Conflicting rates of occult SUI have been reported, with estimates ranging from 36% to 80%.8 Although preoperative urodynamic testing indicates a high rate of occult stress incontinence, a study by Borstad et al9 suggests that the rate of de novo incontinence may be lower and that preoperative urodynamic findings are not predictive of postoperative continence status. In that study, 16 of 73 women (22%) developed stress incontinence following surgery for prolapse when no incontinence procedure was performed. Advanced age increased the risk of incontinence after surgery.
Contrast these findings with those of Chaikin and colleagues,10 who prospectively followed 24 patients with grade 3 or 4 cystoceles. Preoperative urodynamics showed a 58% rate of occult stress incontinence. All these patients were also defined as having intrinsic sphincter deficiency with leak point pressures below 60 cm water. The incontinent group underwent anterior colporrhaphy and concomitant pubovaginal sling, compared with anterior colporrhaphy alone for those without incontinence. Postoperatively, 2 patients who had the pubovaginal sling procedure reported continued stress incontinence (14%). No new symptoms of incontinence were reported in the patients without leakage on preoperative urodynamics. Thus, preoperative urodynamics were 100% accurate in determining which women did not need additional surgery for SUI.
Implications of a negative stress test. Our experience has shown that, despite our best attempts, a negative stress test with the prolapse reduced prior to surgery is less than 100% predictive. Occasionally, new SUI occurs after reconstructive surgery. It is unclear whether this incontinence is caused by straightening the urethra and reducing the bulge or secondary to the dissection of surgery.